This is the first report about Na and K fluxes and heritability of Na exclusion in the Elymus genus. Argentine wheatgrass [Elymus scabrifolius (Döll) J.H. Hunz.] is an important forage genetic resource for saline environments. A previous study showed that salt‐sensitive lines accumulated toxic levels of Na in shoots. The aim of this study was to increase the understanding of Na exclusion in Argentine wheatgrass. Growth and Na and K accumulation rates were analyzed in two homozygous salt‐tolerant genotypes (T1 and T2) and a salt‐sensitive genotype (S1), under different salt stress levels. The Na accumulation rate in shoots was 1.5 times higher in the sensitive line than in the tolerant ones at 100 mM NaCl, and five times higher at 200 mM NaCl. A negative association was found between Na concentration and leaf weight in parent genotypes, F₁, and segregating F₂ populations generated by crossing homozygous S1 and T2, suggesting that growth in the third leaf was more affected in Na‐including genotypes. The inheritance of Na exclusion was estimated under salt stress conditions in a segregating F₂ population and in F_2:3 families obtained by crossing two homozygous genotypes with contrasting values of shoot Na exclusion. In the F₂ population and F_2:3 families, Na concentration segregation was compatible with intermediate inheritance (with very low partial dominance). High heritability values estimated for Na exclusion suggest that this trait might be used as a priority selection criterion for salt tolerance. Results will be useful to design breeding strategies for salt tolerance in this and related species of the Elymus genus.

中文翻译：

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阿根廷小麦草的耐盐性与芽钠的排除有关

这是关于披碱草属植物中Na和K通量以及Na排他性的遗传力的首次报道。阿根廷小麦草[ Elymus scabrifolius（Döll）JH Hunz。]是盐环境中重要的牧草遗传资源。先前的研究表明，盐敏感品系在芽中积累了Na的有毒水平。这项研究的目的是增进对阿根廷小麦草中Na排除的了解。在不同的盐胁迫水平下，分析了两个纯合的耐盐基因型（T1和T2）和一个盐敏感性基因型（S1）的生长以及Na和K积累速率。在100 mM NaCl中，敏感品系中嫩芽中的Na积累率比耐受性品系中的Na积累率高1.5倍，而在200 mM NaCl中则高5倍。在亲本基因型F ₁和分离的F _2中，Na浓度与叶重之间存在负相关关系。杂交纯合S1和T2产生的居群表明，含Na基因型对第三片叶子的生长影响更大。在盐胁迫条件下，在分离的F ₂群体和通过将两个纯合基因型与芽Na排斥值进行对比获得的F _2：3家族中，估计了Na排斥的遗传。在F ₂人口和F _2：3中家族中，Na浓度偏析与中间遗传相容（部分优势很低）。对于Na排除，估计的高遗传力值表明该性状可用作耐盐性的优先选择标准。研究结果对于设计该披碱草属及相关种的耐盐性育种策略很有用。